<template>
  <div>
    <table border="1" width="700" style="border-collapse: collapse">
      <caption>
        购物车
      </caption>
      <thead>
        <tr>
          <th><input type="checkbox" v-model="all" /> <span>全选</span></th>
          <th>名称</th>
          <th>价格</th>
          <th>数量</th>
          <th>总价</th>
          <th>操作</th>
        </tr>
      </thead>
      <tbody>
        <tr v-for="(item, index) in goodList" :key="index">
          <td><input type="checkbox" v-model="item.checked" /></td>
          <td>{{ item.name }}</td>
          <td>{{ item.price }}</td>
          <td>
            <button type="button" @click="less(index)">-</button>
            <span>{{ item.num }}</span>
            <button type="button" @click="plus(index)">+</button>
          </td>
          <td>{{ item.num * item.price }}</td>
          <td><button type="button" @click="deleted(index)">删除</button></td>
        </tr>
      </tbody>
      <tfoot>
        <tr>
          <td>合计:</td>
          <td colspan="5">{{ total }}￥</td>
        </tr>
      </tfoot>
    </table>
  </div>
</template>

<script>
export default {
  data() {
    return {
      goodList: [
        {
          name: "诸葛亮",
          price: 1000,
          num: 1,
          checked: false,
        },
        {
          name: "蔡文姬",
          price: 1500,
          num: 1,
          checked: false,
        },
        {
          name: "妲己",
          price: 2000,
          num: 1,
          checked: false,
        },
        {
          name: "鲁班",
          price: 2200,
          num: 1,
          checked: false,
        },
      ],
    };
  },
  computed: {
    all: {
      get() {
        return this.goodList.every((item) => item.checked === true);
      },
      set(flage) {
        this.goodList.forEach((item) => (item.checked = flage));
      },
    },
    total() {
      const arr = this.goodList.filter((item) => item.checked === true);
      return arr.reduce((sum, item) => (sum + item.price) * item.num, 0);
    },
  },
  methods: {
    plus(index) {
      this.goodList[index].num++;
    },
    less(index) {
      if (this.goodList[index].num === 0) return;
      this.goodList[index].num--;
    },
    deleted(index) {
      this.goodList.splice(index, 1);
    },
  },
};
</script>

<style scoped>
button {
  min-width: 24px;
  height: 18px;
  border: 1px solid #000;
  margin: 0 6px;
  padding: 0 8px;
  cursor: pointer;
}
</style>
